This invention relates to a guide for a sunroof assembly.
Sunroof assemblies typically comprise a sunroof panel moved over a vehicle roof between an open and closed position by cables. A drive unit, such as an electric motor, may move the cables to open and close the sunroof. The sunroof moves from its closed to open position on tracks that extend across the opening of the vehicle roof. Guides on the sunroof are attached to the cables, which draw the sunroof open and closed through these guides. These guides typically comprise slats of metal that slide on the tracks.
When the sunroof is closed, it is preferable that the guides fit tightly on the track so that the sunroof and its associated parts do not rattle. However, a close fit between the guides and the track results in a high level of friction between the guide and track when the sunroof is drawn by the cables of the system. As a consequence, high torque motors are required to drag the sunroof open and closed. High torque motors are not only more expensive and large, but they also require a significant amount of electricity from the vehicle""s electrical system.
A need therefore exists for a vehicle sunroof assembly that reduces the friction between the guide and track of the assembly while still ensuring that the sunroof assembly does not rattle when closed.
The present invention comprises a sunroof assembly with guides that compress as the sunroof panel moves. By compressing, these guides move across the tracks of the sunroof assembly with significantly less friction than existing sunroof guides. Consequently, the inventive assembly permits the use of a smaller motor with the sunroof system. When the sunroof stops moving, the sunroof guides expand in size to fit closely with the track thereby ensuring a close fit between guide and track.
The inventive roof panel assembly comprises a vehicle roof panel and a track to receive the vehicle panel. The inventive assembly has a drive unit that manipulates a cable connected to the roof panel. In contrast to existing sunroof assemblies, however, the inventive sunroof system incorporates at least one guide that has a portion that changes dimension. When the sunroof is not moving, the guide fits closely to the track. When the guide moves, however, the portion changes dimension to thereby reduce the friction between the guide and the track.
The guide may comprise a flexible cross member attached to the drawing cable that reduces in size by flexing. The cable may flex the flexible cross member so that its width changes to a smaller width. A first guide member and a second guide member may be attached to the flexible cross member forming a generally H-shaped guide with curved sides. The first guide member may be in contact with a wall of the track while the second guide member may be in contact with the other wall of the track. The first guide member and the second guide member help secure the guide within the track when the sunroof is still. The guide may be squeezed into the track with the first guide member in contact with one wall and the second guide member in contact with the other wall. When the flexible cross member flexes and reduces in width, the guide moves more freely within the track as the guide members are pulled away from the track walls.
Accordingly, a sunroof may be supported on a track with a guide. A guide portion may alter in dimension when the guide moves along the track. When the guide no longer moves, the guide portion may return to its original size to thereby secure the sunroof to the track. The guide portion may flex between its reduced size and its original size.
In this way, the inventive sunroof assembly permits the use of lower torque motors without adding significant expense.